Of the pollens present in the male organ of plants, anemophilous pollen is dispersed in the air by being carried on the wind, and attaches to the ovule for pollination. When people inhale the pollen, a severe symptom called pollinosis is sometime developed. Particularly, in pollinosis due to pollen of Cryptomeria, Chamaecyparis, Ambrosia and the like, allergic conditions of the eye and nose are developed. The number of people suffering from the pollinosis tends to increase every year.
As a solution for such damages by pollen, administration of antihistamine agents, adrenal cortex hormone and the like, and use of eye drops, wearing masks and the like can be mentioned. The most effective solution is suppressing dispersal of pollen into the air.
As a measure for suppressing dispersal of pollen into the air, cutting down causative trees and plants and weeding can be mentioned. However, cutting down trees and the like are problematic in that they not only require enormous labor but also cause an adverse influence such as destruction of natural environment and the like.
As a means for suppressing dispersal of pollen other than cutting down trees, spraying or applying a certain kind of agent onto the male organ has been proposed. As examples of such agent, vegetable oils and fats containing oleic acid or linoleic acid as a main component (e.g., patent document 1) and those containing sodium oleate (e.g., patent document 2) as an active ingredient have been proposed.
However, since these agents show a comparatively slow efficacy on male flower buds, they are defective in that the timing of spraying of the agent is limited to August when male flower buds are in the initial period of bud differentiation process.    patent document 1: JP-B-8-762    patent document 2: JP-B-2890162